ISSN:
1573-9228
Source:
Springer Online Journal Archives 1860-2000
Topics:
Physics
Notes:
Conclusion In conclusion, we turn attention to the following aspects of the structural investigations of the Ti-Ni system near the equiatom composition, which have not yet received development in practice up to this time. 1. Existing experimental data indicate that the high-temperature TiNi phase has a B2 structure with ordered atom location of CsCl type. Meanwhile, up to now there are no purposeful investigations (firstly by the neutron diffraction method) of the change in the degree of long-range order in TiNi as a function of the temperature and concentration. These investigations are important not only for the setting up of the atomic distribution in the high-temperature phase, they have a direct relationship to the comprehension of the nature of the change in MT temperature and sequence, as well as to the formation of noncommensurate structures in the TiNi system. 2. The passage from the MT sequence B2 → B19′ to B2 → R → B19′ is of great value for the realization of the superelasticity effect and the achievement of large reversible strains in TiNi alloys. Investigations existing at this time indicate that redistribution of the Ti and Ni atoms precedes this passage. However, what changes occur here in the crystalline or electronic structure of the high-temperature phase is not known here. 3. For intermetallides with B2 structure, a high concentration of structural vacancies (especially for deviations from the stoichiometric composition) that can exert noticeable influence on the phase transformations is not unusual. However, up to now there are no investigations of the change in vacancy concentration in TiNi alloys as a function of the temperature and concentration of the Ti and Ni atoms.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00892272
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